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<a name="boost.log.attribute.impl"></a><div class="titlepage"></div>
<div class="refnamediv">
<h2><span class="refentrytitle">Struct impl</span></h2>
<p>boost::log::attribute::impl — A base class for an attribute value factory. </p>
</div>
<h2 class="refsynopsisdiv-title">Synopsis</h2>
<div class="refsynopsisdiv"><pre class="synopsis"><span class="comment">// In header: &lt;<a class="link" href="../../../attributes.html#header.boost.log.attributes.attribute_hpp" title="Header &lt;boost/log/attributes/attribute.hpp&gt;">boost/log/attributes/attribute.hpp</a>&gt;

</span>

<span class="comment">// A base class for an attribute value factory.</span>

<span class="keyword">struct</span> <a class="link" href="impl.html" title="Struct impl">impl</a> <span class="special">:</span> <span class="keyword">public</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">intrusive_ref_counter</span><span class="special">&lt;</span> <span class="identifier">impl</span> <span class="special">&gt;</span> <span class="special">{</span>
  <span class="comment">// <a class="link" href="impl.html#boost.log.attribute.implconstruct-copy-destruct">construct/copy/destruct</a></span>
  <span class="keyword">virtual</span> <a class="link" href="impl.html#idm23735-bb"><span class="special">~</span><span class="identifier">impl</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span>

  <span class="comment">// <a class="link" href="impl.html#idm23727-bb">public member functions</a></span>
  <span class="keyword">virtual</span> <a class="link" href="../attribute_value.html" title="Class attribute_value">attribute_value</a> <a class="link" href="impl.html#idm23728-bb"><span class="identifier">get_value</span></a><span class="special">(</span><span class="special">)</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span>

  <span class="comment">// <a class="link" href="impl.html#idm23737-bb">public static functions</a></span>
  <span class="keyword">static</span> <span class="keyword">void</span> <span class="special">*</span> <a class="link" href="impl.html#idm23738-bb"><span class="keyword">operator</span> <span class="keyword">new</span></a><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span><span class="special">)</span><span class="special">;</span>
  <span class="keyword">static</span> <span class="keyword">void</span> <a class="link" href="impl.html#idm23742-bb"><span class="keyword">operator</span> <span class="keyword">delete</span></a><span class="special">(</span><span class="keyword">void</span> <span class="special">*</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span><span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span>
<span class="special">}</span><span class="special">;</span></pre></div>
<div class="refsect1">
<a name="idm27424"></a><h2>Description</h2>
<p>All attributes must derive their implementation from this class. </p>
<div class="refsect2">
<a name="idm27427"></a><h3>
<a name="boost.log.attribute.implconstruct-copy-destruct"></a><code class="computeroutput">impl</code> 
        public
       construct/copy/destruct</h3>
<div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem">
<pre class="literallayout"><span class="keyword">virtual</span> <a name="idm23735-bb"></a><span class="special">~</span><span class="identifier">impl</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre>Virtual destructor. </li></ol></div>
</div>
<div class="refsect2">
<a name="idm27442"></a><h3>
<a name="idm23727-bb"></a><code class="computeroutput">impl</code> public member functions</h3>
<div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem">
<pre class="literallayout"><span class="keyword">virtual</span> <a class="link" href="../attribute_value.html" title="Class attribute_value">attribute_value</a> <a name="idm23728-bb"></a><span class="identifier">get_value</span><span class="special">(</span><span class="special">)</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span></pre>
<p>
</p>
<div class="variablelist"><table border="0" class="variablelist compact">
<colgroup>
<col align="left" valign="top">
<col>
</colgroup>
<tbody><tr>
<td><p><span class="term">Returns:</span></p></td>
<td><p>The actual attribute value. It shall not return empty values (exceptions shall be used to indicate errors). </p></td>
</tr></tbody>
</table></div>
</li></ol></div>
</div>
<div class="refsect2">
<a name="idm27465"></a><h3>
<a name="idm23737-bb"></a><code class="computeroutput">impl</code> public static functions</h3>
<div class="orderedlist"><ol class="orderedlist" type="1">
<li class="listitem"><pre class="literallayout"><span class="keyword">static</span> <span class="keyword">void</span> <span class="special">*</span> <a name="idm23738-bb"></a><span class="keyword">operator</span> <span class="keyword">new</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> size<span class="special">)</span><span class="special">;</span></pre></li>
<li class="listitem"><pre class="literallayout"><span class="keyword">static</span> <span class="keyword">void</span> <a name="idm23742-bb"></a><span class="keyword">operator</span> <span class="keyword">delete</span><span class="special">(</span><span class="keyword">void</span> <span class="special">*</span> p<span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> size<span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span></pre></li>
</ol></div>
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<div class="copyright-footer">Copyright © 2007-2024 Andrey Semashev<p>
        Distributed under the Boost Software License, Version 1.0. (See accompanying
        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>).
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